The funeral of a soldier shot in Afghanistan by a man dressed in a local police uniform will be held later on Tuesday at Llandaff Cathedral, Cardiff.
Craig Roderick, of 1st Battalion Welsh Guards, was one of three British troops killed as they left a checkpoint.
The 22-year-old, of Llanharan, Rhondda Cynon Taf, was a former pupil of Pencoed Comprehensive School, Bridgend.
His family said that words could not describe "how the loss of our precious Craig has affected us all".
The soldiers were part of a Nato-led force that had been training Afghan counterparts ahead of a handover of security responsibility by 2014.
The shooting happened at a checkpoint in Helmand province where the soldiers were attending a meeting of elders.
The others killed in the incident were Apete Tuisovurua, also of 1st Battalion Welsh Guards, and Warrant Officer Perran Thomas, of the Royal Corps of Signals.